JP7325401B2 - Manufacture of composite materials made of films, solid adhesive polymers and polyurethane layers - Google Patents

Description

The present invention relates to a method for producing multilayer composites and to multilayer composites obtainable by this method.

Plastic films are required in many applications, such as wrapping. Its mechanical properties, its appearance and its feel are in high demand for some applications. Thus, for example, highly transparent plastic films are very popular as wrapping materials for articles such as shirts, cigarettes, greeting cards, books or tablecloths.

Plastic films are of particular importance in the manufacture of electronic products, such as mobile phones. Especially since they can be thermoformed and adapted very easily to the shape of the relevant application.

WO2009/106500 describes composites made of films with polyurethane layers and their production.

WO2009/106500

The aim is to make available a method that allows the production of multilayer composite systems. The composite system should exhibit better layer adhesion than known composite systems.

The subject of the present invention is
(A) films based on polyurethane or polyamide,
(B) a tie layer made of a thermoplastic adhesive polymer having a melting point of 70° C. to 130° C.; and (C) a polyurethane layer, comprising:
here,
a) using a mold to form a polyurethane layer (C),
b) applying the adhesive polymer in solid form to the film (A) and/or the polyurethane layer (C), and c) combining the polyurethane layer (C) with the film (A),
The method.

The present invention further provides
(A) films made of polyurethane or polyamide;
(B) a tie layer made of a thermoplastic adhesive polymer having a melting point between 70° C. and 130° C.; and (C) a polyurethane layer.

The method according to the invention generally uses a flat substrate as film (A). A flat substrate, in the context of the present invention, is one whose extension in two dimensions is much greater than in the third dimension; , may exceed the thickness by a factor of at least 100 and preferably by a factor of at least 1000. In one embodiment, the length and/or width of film (A) exceeds the thickness by a factor of 1,000,000. The length and width of film (A) may be the same or, preferably, different in each case. For example, the length of film (A) may exceed the width by 1.1 to 100 times.

In one embodiment of the invention, the length of film (A) ranges from 50 cm to 100 m, preferably up to 50 m and particularly preferably up to 10 m. In one embodiment of the invention, the width of film (A) ranges from 10 cm to 5 m, preferably 2 m.

In one embodiment of the invention, the thickness of film (A) ranges from 50 nm to 2 mm, preferably from 1 μm to 500 μm and especially from 20 μm to 300 μm.

In one embodiment, film (A) is an "endless material" and is generally rolled and unrolled and used in a continuous process. In this connection, the length of the rolled film (A) exceeds its width by many times.

Film (A) is preferably bendable manually, ie without the use of tools.

In one embodiment of the invention, the flat substrate, in particular the film (A), presents a modulus of elasticity in the range from 200 to 5000 N/mm ² , determinable according to DIN 53455, for example. Modulus of elasticity in the range 200 to 1000 N/ ^mm2 , for example predominantly with polyethylene (HDPE or LDPE), for example in the range of 1000 to 3500 N/ ^mm2 predominantly with unplasticized PVC, or 4000 to 4500 N/mm2 predominantly with PET. Flat substrates, especially films, with a modulus of elasticity in the mm ² range are particularly suitable.

The film can contain additives. Suitable additives can be selected, for example, from plasticizers, impact modifiers, stabilizers, colorants, fillers, reinforcing agents, flame retardants, light stabilizers and waxes.

Film (A) can exhibit a weight per unit area ranging from 10 to 3000 g/m ² ; 50 to 300 g/cm ² is preferred.

Suitable films (A) are based on polyurethanes or polyamides. The majority of the film comprises at least 50% by weight, preferably at least 80% by weight and especially at least 90% by weight of polymer (such as polyurethane or polyamide). In a preferred form, the film is based on polyurethane, especially thermoplastic polyurethane. In a preferred form, the film is based on polyamide. The film is preferably made of thermoplastic polyurethane or aliphatic polyamide.

The film can be constructed by combining individual films. The expression that the film is polymer-based refers to a composite film and refers to the individual films forming the surface of the composite film.

Suitable polyamides for films are aliphatic, partially aromatic and aromatic polyamides, with aliphatic polyamides being preferred. Homopolyamides and copolyamides are suitable.

A suitable partially aromatic polyamide is PA6T made from hexamethylenediamine and terephthalic acid (PA6T).

Suitable aromatic polyamides are based on para-phenylenediamine and terephthalic acid.

Suitable aliphatic polyamides are based on monomers such as caprolactam, hexamethylenediamine, adipic acid, sebacic acid.

Examples of polyamides are PA6/66 made from caprolactam, hexamethylenediamine and adipic acid, PA66/610 made from hexamethylenediamine, adipic acid and sebacic acid, PA6.6 made from hexamethylenediamine and adipic acid. 6, and PA6 made with caprolactam.

The polyamide is in particular PA 6/66 made from caprolactam, hexamethylenediamine and adipic acid.

Suitable polyurethanes for the film are those described below for the polyurethane layer (C), preferably thermoplastic polyurethanes, as described below.

Preferred polyurethanes for films are polyester polyurethanes or polyether polyurethanes. Polyester polyurethanes, especially aromatic polyester polyurethanes, are particularly preferred.

Polyurethanes suitable for films are generally free of plasticizers and/or solvents. Most polyurethanes suitable for films have softening points between 80°C and 120°C.

The composite material comprises a tie layer (B) of thermoplastic adhesive polymer having a melting point of 70°C to 130°C. Tie layer (B) can be, for example, a separate layer, preferably a cured organic adhesive layer, which is perforated, ie the surface is not completely intact.

In one embodiment, the tie layer (B) presents a thickness in the range from 1 up to 100 μm, preferably up to 50 μm, particularly preferably up to 15 μm.

The adhesive polymer is applied to the film (A) and/or polyurethane layer (C) in solid form.

The majority of the adhesive polymers in step b) have a weight per unit area of 0.1 to 1000 g/m ² , preferably 1 to 300 g/m ² , especially 5 to 100 g/m ² .

Most of the adhesive polymers in step b) have a melt volume flow rate MVR of 1 to 500 cm ³ /10 min, preferably 5 to 200 cm ³ /10 min and especially 10 to 100 cm ³ /10 min. Melt volume flow rate MVR can be measured at 160° C. and 2.16 kg according to ISO 1133-1.

The adhesive polymer preferably has a melting point of 80°C to 125°C, and especially 85°C to 120°C. Melting points can be determined using DSC, eg according to ISO 11357.

The adhesive polymer can be applied in step b) in the form of an adhesive grid, adhesive web or adhesive film.

The adhesive grid can exhibit round or angular (eg square, triangular or hexagonal) openings.

The adhesive web may comprise randomly assembled fibers.

Adhesive films can form sheets that have a perfectly intact surface and are generally devoid of apertures.

The adhesive polymer is in solid form, eg as an adhesive grid, adhesive web or adhesive film, and is commercially available from AB-Tec GmbH & Co., for example. KG, Iserlohn, Germany; Spunfab Ltd.; , Cuyahoga Falls, USA; or Protechnic S.A.; A. , Cernay, France.

Adhesive polymers can be based on polyurethanes, polyamides, polyesters or polyolefins.

Suitable polyurethanes for the adhesive polymer are those mentioned below for the polyurethane layer (C), preferably thermoplastic polyurethanes, especially aliphatic thermoplastic polyurethanes, mentioned below.

Suitable polyamides are copolyamides.

Suitable polyesters are polyethylene terephthalate (PET) and PET copolymers.

Suitable polyolefins include polyethylene (e.g. low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), linear medium density polyethylene (LMDPE), linear very low density (very -low density polyethylene (VLDPE), linear ultra-low density polyethylene (ULDPE), high density polyethylene (HDPE)) and copolymers of polyethylene. Examples of copolymers of polyethylene are ethylene/vinyl acetate, ethylene/vinyl alcohol, ethylene/octene or ethylene/acrylic acid, eg as described in WO2003064153.

In one embodiment, the tie layer (B), also as layer (C), contains one or more additives such as one or more flame retardants, stabilizers such as antioxidants, light stabilizers and/or waterproofing agents. Or an anti-oil agent can optionally be included.

Suitable flame retardants are, for example, inorganic flame retardants, halogenated organic compounds, organophosphorus compounds or halogenated organophosphorus compounds.

Suitable inorganic flame retardants are, for example, phosphates such as ammonium phosphate, aluminum hydroxide, alumina trihydrate, zinc borate or antimony oxide.

Suitable halogenated organic compounds are, for example, chloroparaffins, polychlorinated biphenyls, hexabromobenzenes, polybrominated diphenyl ethers (PBDEs) and other brominated compounds such as the addition products of hexachlorocyclopentadiene with cyclooctadiene, tetra Bromobisphenol A, tetrabromophthalic anhydride, and dibromoneopentyl glycol.

Suitable organic phosphorus compounds are, for example, organic phosphates, phosphites and phosphonates such as tricresyl phosphate and tert-butylphenyldiphenyl phosphate.

Suitable halogenated organophosphorus compounds are, for example, tris(2,3-dibromopropyl)phosphate, tris(2-bromo-4-methylphenyl)phosphate and tris(2-chloroisopropyl)phosphate.

Preferred flame retardants are, for example, polyvinyl chloride or polyvinylidene chloride and copolymers of (meth)acrylic acid esters and vinylidene chloride. Such products are sold, for example, under the trade name Diofan®.

Suitable light stabilizers are, for example, radical scavengers, such as sterically hindered organic amines (HALS), or peroxide decomposers, such as 2-(2-hydroxyphenyl)-2H-benzotriazole (BTZ) or hydroxybenzophenone (BP) and other benzotriazoles. Additional suitable light stabilizers are for example (2-hydroxyphenyl)-s-triazine (HPT), oxalanilides or nonpigmentary titanium dioxide. Suitable light stabilizers can be purchased, for example, under the trade names Irganox®, Irgastab® or Tinuvin®. Preferred light stabilizers are HALS compounds.

Thermoplastic polyurethanes are suitable as polyurethane layer (C). Suitable polyurethanes are preferably all thermoplastic polyurethanes which can be provided in the form of an aqueous dispersion. They preferably have a glass transition temperature below 0° C. determined by DSC (differential scanning calorimetry), for example according to DIN 53765. Preferably, polymer layer (C) consists essentially of polyurethane.

Polyurethanes (PUs) are generally known and commercially available and generally contain relatively high molecular weight polyhydroxyl compounds such as a soft phase of polycarbonate, polyester or polyether segments, and low molecular weight chain extenders and di- or polyether segments. It consists of a urethane hard phase formed from isocyanates.

Methods for producing polyurethanes (PU) are generally known. Polyurethanes (PU) are generally
(i) an isocyanate, preferably a diisocyanate, and
(ii) isocyanate-reactive compounds having a molecular weight (M _w ) of generally 500 to 10 000 g/mol, preferably 500 to 5000 g/mol, particularly preferably 800 to 3000 g/mol, and (iii) 50 to 499 g/mol. optionally in the presence of (iv) a catalyst (v) and/or conventional additives, with a chain extender having a molecular weight of
Manufactured by reaction.

In the following, the starting components and the process for the production of preferred polyurethanes (PU) are described by way of example. The components (i), (ii), (iii) and optionally (iv) and/or (v) customarily used in the production of polyurethanes (PU) are listed below by way of example:
As isocyanate (i), generally known aliphatic, cycloaliphatic, araliphatic and/or aromatic isocyanates, such as tri-, tetra-, penta-, hexa-, hepta- and/or octamethylene diisocyanate , 2-methyl-1,5-pentamethylene diisocyanate, 2-ethyl-1,4-butylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,4-butylene diisocyanate, 1-isocyanato-3,3,5-trimethyl -5-(isocyanatomethyl)cyclohexane (isophorone diisocyanate, IPDI), 1,4- and/or 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 1,4-cyclohexanediisocyanate, 1-methyl-2 ,4- and/or -2,6-cyclohexane diisocyanate and/or 4,4′-, 2,4′- and/or 2,2′-dicyclohexylmethane diisocyanate, 2,2′-, 2,4′- and/or 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4- and/or 2,6-toluylene diisocyanate (TDI), 3,3'-dimethyldiphenyl Diisocyanates, 1,2-diphenylethane diisocyanate and/or phenylene diisocyanate may be used. 4,4'-MDI is preferably used. Aliphatic diisocyanates, especially hexamethylene diisocyanate (HDI) are more preferred, aromatic diisocyanates such as 2,2′-, 2,4′- and/or 4,4′-diphenylmethane diisocyanate (MDI) and mixtures of the above isomers. is particularly preferred.

As isocyanate-reactive compounds (ii) there may be used generally known isocyanate-reactive compounds such as polyesterols, polyetherols and/or polycarbonate diols, which are usually under the term "polyols" have a molecular weight (M _w ) in the range from 500 to 8000 g/mol, preferably from 600 to 6000 g/mol and especially from 800 to 3000 g/mol and preferably from 1.8 to 2.3, preferably 1.9 to 2.2 and especially 2, combined with an average functionality with respect to isocyanates. Polyether polyols, such as those based on commonly known starting materials, and customary alkylene oxides such as ethylene oxide, 1,2-propylene oxide and/or 1,2-butylene oxide, preferably polyoxytetramethylene ( Polyetherols based on poly-THF), 1,2-propylene oxide and ethylene oxide are preferably used. Polyetherols present the advantage that they have a greater stability towards hydrolysis than polyesterols and are preferred as component (ii) for the production of flexible polyurethanes (PU1).

Polycarbonate diols include in particular aliphatic polycarbonate diols such as 1,4-butanediol polycarbonate and 1,6-hexanediol polycarbonate.

As polyester diols, on the one hand, at least one primary diol, preferably at least one primary aliphatic diol, such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol or particularly preferably 1,4-di(hydroxymethyl)cyclohexane (as isomer mixture) or a mixture of at least two of the above diols and on the other hand at least one, preferably at least two dicarboxylic acids or their anhydrides and those that can be produced by polycondensation of substances. Preferred dicarboxylic acids are aliphatic dicarboxylic acids such as adipic acid, glutaric acid or succinic acid, and aromatic dicarboxylic acids such as phthalic acid and especially isophthalic acid.

Polyetherols are preferably alkylene oxides, in particular ethylene oxide, propylene oxide and mixtures thereof, for example ethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 1,4-butanediol or 1,4-butanediol. It is prepared by addition to a diol such as 3-propanediol or to a triol such as glycerol in the presence of a highly active catalyst. Such highly active catalysts are for example cesium hydroxide and double metal cyanide catalysts, also described as DMC catalysts. A frequently used DMC catalyst is zinc hexacyanocobaltate. The DMC catalyst may remain in the polyetherol after reaction; preferably it is removed, for example by settling or filtration.

Mixtures of different polyols can also be used in place of one polyol.

のアルカリ金属塩又はアンモニウム塩を使用してよい。 A proportion of one or more diols or diamines (b′) with carboxylic or sulfonic acid groups, in particular 1,1-dimethylol, as compounds (ii) which react with isocyanates to improve dispersibility butanoic acid, 1,1-dimethylolpropionic acid or

may be used.

As chain extenders (iii), aliphatic, araliphatic, aromatic and/or cycloaliphatic compounds having a molecular weight of 50 to 499 g/mol and at least two functional groups, preferably known per se Compounds with exactly two functional groups per molecule, for example alkanediols with 2 to 10 carbon atoms in the diamine and/or alkylene groups, in particular 3 to 8 carbon atoms per molecule 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and/or di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and/or deca Alkylene glycols, preferably corresponding oligo- and/or polypropylene glycols, are used. It is also possible to use mixtures of chain extenders (iii).

Components (i) to (iii) are particularly preferably difunctional compounds, i.e. diisocyanates (i), difunctional polyols, preferably polyetherols (ii), and difunctional chain extenders, preferably is a diol.

Suitable catalysts (iv) which particularly promote the reaction between the NCO groups of diisocyanate (i) and the hydroxyl groups of components (ii) and (iii) are, for example, triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N , N′-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo(2.2.2)octane (“DABCO”) and similar tertiary amines, and especially organometallic compounds, For example titanate esters, iron compounds such as iron(III) acetylacetonate, tin compounds such as tin diacetate, tin dioctoate, tin dilaurate or dialkyltin salts of aliphatic carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate, etc., which are known per se. The catalyst is generally used in an amount of 0.0001 to 0.1 parts by weight per 100 parts by weight of component (ii).

In addition to catalyst (iv), auxiliaries and/or additives (v) may be added to components (i) to (iii). For example, foaming agents, antiblocking agents, surface-active substances, fillers, e.g. nanoparticle-based fillers, in particular _CaCO3 -based fillers, also nucleating agents, lubricants, dyes and pigments, antioxidants agents such as antioxidants against hydrolysis, light, heat or discoloration, inorganic and/or organic fillers, reinforcing agents and plasticizers, or metal deactivators. In preferred embodiments, component (v) also includes hydrolysis stabilizers such as polymeric carbodiimides and low molecular weight carbodiimides. The flexible polyurethanes preferably contain triazoles and/or triazole derivatives and antioxidants in an amount of 0.1 to 5% by weight relative to the total weight of the flexible polyurethanes concerned. Suitable as antioxidants are generally substances which counteract or prevent undesired oxidation processes in the plastics to be protected. Generally, antioxidants are commercially available. Examples of antioxidants are sterically hindered phenols, aromatic amines, thiosynergists, organophosphorus compounds of trivalent phosphorus, and hindered amine light stabilizers. Examples of sterically hindered phenols are found in Plastics Additive Handbook, 5th Ed. Zweifel, ed., Hanser Publishers, Munich, 2001 ([1]), pages 98-107 and 116-121. Examples of aromatic amines are found in [1] pages 107-108. Examples of thiosynergists are given in [1], pages 104-105 and 112-113. Examples of phosphites are found in [1], pages 109-112. Examples of hindered amine light stabilizers are given in [1], pages 123-136. Phenolic antioxidants are preferably suitable for use in the antioxidant mixture. In a preferred embodiment, the antioxidants, in particular phenolic antioxidants, exhibit a molar mass of more than 350 g/mol, particularly preferably more than 700 g/mol, with a maximum molar mass (Mw) of up to 10 000 g/mol, preferably is up to 3000 g/mol. Furthermore, they preferably have a melting point of at most 180°C. In addition, preferably amorphous or liquid antioxidants are used. Likewise, mixtures of two or more antioxidants can be used as component (v).

In addition to the described components (i), (ii) and (iii) and optionally (iv) and (v), chain regulators (chain terminators) are used, usually having a molecular weight of from 31 to 3000 g/mol. may Such chain regulators are compounds presenting only one functional group that reacts with isocyanates, for example monofunctional alcohols, monofunctional amines and/or monofunctional polyols. Flow behavior can be selectively adjusted via such chain regulators, especially with flexible polyurethanes. Chain regulators can generally be used in an amount of 0 to 5 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of component (ii), and are defined as component (iii) to go into.

In addition to components (i), (ii) and (iii) and optionally (iv) and (v) described, also cross-linking agents having two or more groups reactive with isocyanate, such as hydrazine hydrate, It can be used towards the end of the synthetic reaction.

Components (ii) and (iii) can be selected in relatively wide molar ratios to adjust the hardness of the polyurethane (PU). A molar ratio of component (ii) used to total chain extender (iii) of 10:1 to 1:10, in particular 1:1 to 1:4, has proven to be beneficial and has been shown to be beneficial for flexible polyurethanes. Hardness increases with increasing content of (iii). The reaction for the preparation of polyurethanes (PU) has an index of 0.8 to 1.4:1, preferably an index of 0.9 to 1.2:1, particularly preferably 1.05 to 1.2:1. can be implemented with the exponent of The index is a measure of all isocyanate groups of component (i) used in the reaction of component (ii) and optionally (iii) and optionally monofunctional components which react with isocyanates as chain terminators, for example monoalcohols. is defined by the ratio of to the isocyanate-reactive groups, ie, active hydrogens.

The production of polyurethanes (PU) can be carried out by processes known per se, continuously, for example by one-shot or prepolymer processes, or batchwise by prepolymer operations known per se. In these processes the components (i), (ii), (iii) and optionally (iv) and/or (v) to be reacted can be mixed with one another sequentially or simultaneously and the reaction begins immediately. .

Polyurethanes (PU) are prepared by methods known per se, for example by dissolving the polyurethane (PU) in acetone or by preparing the polyurethane as a solution in acetone, adding water and then removing the acetone, for example by distillation. can be dispersed in water by In an alternative form, the polyurethane (PU) is prepared as a solution in N-methylpyrrolidone or N-ethylpyrrolidone and water is added to remove the N-methylpyrrolidone or N-ethylpyrrolidone.

In one embodiment of the invention, the aqueous dispersion according to the invention comprises two different polyurethanes, polyurethane (PU1) and polyurethane (PU2), of which polyurethane (PU1) is polyurethane (PU) as defined above. and at least one is a rigid polyurethane (PU2).

Rigid polyurethanes (PU2) can in principle be prepared analogously to soft polyurethanes (PU1); however, other compounds (ii) that react with isocyanates or other mixtures of compounds (ii) that react with isocyanates is selected as compound (ii-2), or in short compound (ii-2), which reacts with isocyanates as described in the context of the present invention.

Examples of compounds (ii-2) are especially mixtures of 1,4-butanediol, 1,6-hexanediol and neopentyl glycol with each other or with polyethylene glycol.

In an alternative form of the invention, a mixture of diisocyanates, for example a mixture of HDI and IPDI, is each time chosen as diisocyanate (i) for the polyurethane (PU2), a larger proportion of IPDI than for the production of the flexible polyurethane (PU1). are also selected for the production of rigid polyurethanes (PU2).

In one embodiment of the invention, the polyurethane (PU2) exhibits a Shore A hardness ranging from over 60 to at most 100, the Shore A hardness being determined according to DIN 53505 after 3 seconds.

In one embodiment of the invention, the polyurethane (PU) exhibits an average particle size in the range 100-300 nm, preferably 120-150 nm, determined by laser light scattering.

In one embodiment of the invention, the flexible polyurethane (PU1) exhibits an average particle size in the range 100-300 nm, preferably 120-150 nm, determined by laser light scattering.

In one embodiment of the invention, the polyurethane (PU2) exhibits an average particle size in the range 100-300 nm, preferably 120-150 nm as determined by laser light scattering.

The polymer layer (C) is preferably a polyurethane layer, a PVC layer, a layer of epoxy resin, a polyacrylate layer or a polybutadiene layer, particularly preferably a polyurethane layer. Polymer layer (C) is particularly preferably a polyurethane layer.

In one embodiment of the invention, the polymer layer (C) presents an average thickness in the range from 15 to 300 μm, preferably from 20 to 150 μm, particularly preferably from 25 to 80 μm.

In one embodiment of the invention, the polymer layer (C) presents on average at least 100, preferably at least 250 and particularly preferably at least 1000 capillaries per 100 cm ² .

In one embodiment of the invention the capillaries exhibit an average diameter in the range 0.005 to 0.05 mm, preferably 0.009 to 0.03 mm.

In one embodiment of the invention, the capillaries are evenly distributed over the polymer layer (C). However, in a preferred embodiment of the invention, the capillaries are non-uniformly distributed over the polymer layer (C).

In one embodiment of the invention, the capillaries are curved in nature. In another embodiment of the invention, the capillaries exhibit an essentially linear course.

The capillaries provide permeability to air and water vapor on the polymer layer (C) without the need for perforations. In one embodiment of the invention, the permeability to water vapor of the polymer layer (C) may be greater than 1.5 mg/cm ² ·h measured according to DIN53333. Thus it is possible, for example, that a liquid containing an active compound can move through the polymer layer (C).

In one embodiment of the invention, the polymer layer (C) exhibits capillaries and even pores extending no more than the entire thickness of the polymer layer (C).

In one embodiment the polymer layer (C), in particular the polyurethane layer (C), presents a pattern. The pattern can be any pattern and can, for example, reproduce the pattern of a leather or wood surface. In one embodiment of the invention, the pattern can replicate nubuck leather.

In one embodiment of the invention, the polymer layer (C), especially the polyurethane layer (C) presents a smooth appearance.

In one embodiment of the invention, the pattern corresponds to a smooth surface, e.g. characterized by small crinite with an average length of 20 to 500 μm, preferably 30 to 200 μm, particularly preferably 60 to 100 μm. can. A small tuft feature can exhibit, for example, a circular diameter. In a particular embodiment of the invention, the small tuft features have a conical shape.

In one embodiment of the invention, the polymer layer (C), in particular the polyurethane layer (C), exhibits the characteristics of small tufts arranged at an average distance of 50 to 350 μm, preferably 100 to 250 μm from each other.

In the case where the polymer layer (C), in particular the polyurethane layer (C), exhibits the characteristics of small tufts, said statement regarding the average thickness is also applicable to the polymer layer (C), in particular the polyurethane layer (C), which does not have the characteristics of small tufts. ).

In another embodiment the polymer layer (C), in particular the polyurethane layer (C), presents letters, logos or pictures. In one embodiment the polymer layer (C), in particular the polyurethane layer (C) presents a complex picture as described in WO2012/072740.

In a preferred embodiment, the polymer layer (C), in particular the polyurethane layer (C), is formed from an aqueous polymer dispersion, preferably a polyurethane dispersion, comprising at least one crosslinker C, wherein the at least one crosslinker C is , at least one polyisocyanate P blocked with at least one blocking agent BA.

In a particularly preferred embodiment of the invention, the aqueous polymer/polyurethane dispersion for the production of the connecting layer (B) and/or the polymer layer (C), in particular the polyurethane layer (C), contains from 0.1 to 5% by weight of Contains dipropylene glycol dimethyl ether and/or 1,2-propanediol diacetate.

In a particularly preferred embodiment, suitable crosslinkers C are as a 1 to 80% by weight solution in dipropylene glycol dimethyl ether and/or 1,2-propanediol diacetate, preferably dipropylene glycol dimethyl ether and/or 1,2 - added as a 30 to 75% by weight solution in propanediol diacetate to the aqueous polymer/polyurethane dispersion.

In a particularly preferred embodiment, the polyisocyanate crosslinker C is added to the aqueous polymer/polyurethane dispersion as a 30 to 75% by weight solution in dipropylene glycol dimethyl ether and/or 1,2-propanediol diacetate.

In most cases, layer (C) comprises at least one polyisocyanate P blocked with blocking agent BA. Suitable polyisocyanates P and blocking agents BA are described further above. The blocking agent BA-blocked polyisocyanates P present in layer (C) may be the same or different.

The method according to the invention is generally carried out as follows.

a) using a mold to form a polyurethane layer (C),
b) applying the adhesive polymer in solid form to the film (A) and/or the polyurethane layer (C), and c) combining the polyurethane layer (C) with the film (A).

Step (a) can be performed as follows.

The mold is preferably a silicone mold. A silicone template, in the context of the present invention, is one in which at least one binder presenting at least 1, preferably at least 3 O--Si(R ¹ R ² )--O-- groups per molecule is used in its manufacture. It is understood to mean a template. In this connection, R ¹ and, if present, R ² are different or preferably identical and are selected from organic radicals, preferably C ₁ -C ₆ -alkyl, especially methyl.

In one embodiment of the invention, the silicone mold is a structured silicone mold using laser engraving.

In another embodiment, the mold is a mold made of ethylene/propylene rubber (EPM) or ethylene/propylene/diene rubber (EPDM).
In one embodiment of the invention, the mold made of EPM or EPDM is a structured mold using laser engraving.

An aqueous polymer dispersion (thus for example polyurethane) is applied to a preheated mold and the water is allowed to evaporate.

Application of the aqueous polymer dispersion to the mold can be carried out according to methods known per se, in particular by spraying, for example with a spray gun.

The template exhibits a pattern, also known as structuring, which is produced, for example, by laser engraving or by molding.

If it is desired to structure the mold using laser engraving, then by heating (thermochemically), by irradiating with UV light (photochemically) or by highly It is preferred to strengthen the laser-engravable layer by irradiation with energetic radiation (actinically) or any combination thereof.

Subsequently, laser-engravable layers or layer composites made of plastics, glass-fibre reinforced plastics, metals or foams, for example using adhesive tapes, vacuum, clamping devices or magnetic forces, as described above. Applied to a cylindrical (temporary) substrate that has been engraved into Alternatively, planar layers or layer composites can be engraved as described above. Optionally, during the laser engraving operation, the laser-engravable layer is cleaned using a rotary cylindrical washer or continuous washer with a cleaning agent to remove engraving residue.

In the manner described, the mold can be produced as a negative mold or as a positive mold.

In a first alternative, the mold presents a negative structure, so that the coating can be directly bonded to the film (A) by applying a liquid plastic material to the surface of the mold and subsequently solidifying the polymer. can get.

In a second alternative, the mold presents a positive structure, so that a negative mold is first produced from a laser-structured positive mold by molding. By subsequently applying a liquid plastic material to the surface of the negative mold and subsequently solidifying the plastic material, a coating is obtained from this negative mold which can be bonded to a flat substrate.

Preferably, structural elements having dimensions in the range from 10 to 500 μm are engraved into the mold. Structural elements can be formed as elevations or depressions. The structural elements preferably have simple geometric shapes, such as circles, ellipses, squares, rhombuses, triangles and stars. The structural elements can form regular or irregular screens. Examples are classical dot screens or stochastic screens, eg frequency modulated screens.

In one embodiment of the invention, wells are incorporated into the mold during structuring of the mold using a laser, the wells having an average depth ranging from 50 to 250 μm and a center to center ranging from 50 to 250 μm. exhibit spacing.

For example, the template can be sculpted to exhibit "wells" (depressions) exhibiting diameters in the range of 10 to 500 μm on the surface of the template. The diameter on the surface of the template is preferably 20 to 250 μm, particularly preferably 30 to 150 μm. The well spacing may be, for example, 10 to 500 μm, preferably 20 to 200 μm, particularly preferably up to 80 μm.

In one embodiment of the invention, the template preferably exhibits a fine surface structure in addition to the rough surface structure. Both coarse and fine structures can be produced by laser engraving. The fine structure may be micro-roughness, for example with a roughness amplitude in the range 1 to 30 μm and a roughness frequency in the range 0.5 to 30 μm. The dimensions of the microroughness are preferably in the range from 1 to 20 μm, particularly preferably from 2 to 15 μm, particularly preferably from 3 to 10 μm.

IR lasers are particularly suitable for laser engraving. However, it is also possible to use lasers with shorter wavelengths, as long as the laser exhibits a satisfactory intensity. For example, a frequency-doubled (532 nm) or frequency-tripled (355 nm) Nd-YAG laser, or an excimer laser (eg, 248 nm) can also be used. A CO ₂ laser with a wavelength of 10640 nm can be used, for example, for laser engraving. Lasers with wavelengths from 600 to 2000 nm are particularly preferably used. For example, Nd-YAG lasers (1064 nm), IR diode lasers or solid state lasers can be used. Nd/YAG lasers are particularly preferred. Image information to be engraved is transferred directly from the layout computer system to the laser tool. Lasers can be operated either continuously or in a pulsed mode.

Generally, the resulting template can be used directly after it has been manufactured. If desired, the resulting template can still be washed subsequently. Layer components that have been loosened from the surface, but perhaps not yet completely removed, are removed by such a cleaning step. Generally, a simple treatment with preferably low-swelling water, water/surfactants, alcohols or inert organic detergents is sufficient.

In an additional step, an aqueous formulation of polymer is applied to the mold. Application can preferably be carried out by spraying. When applying a blend of polymers, the mold should be heated to a temperature of, for example, at least 80°C, preferably at least 90°C. Water from the aqueous formulation of polymer evaporates and forms capillaries as the polymer layer solidifies.

Aqueous, in connection with the polymer dispersion, is understood to mean that it contains water, but less than 5% by weight, preferably less than 1% by weight, of organic solvents, based on the dispersion. Particularly preferably, no volatile organic solvents can be detected. Volatile organic solvents are understood in the context of the present invention to mean organic solvents exhibiting a boiling point of up to 200° C. at standard pressure.

In one embodiment of the present invention, the aqueous polymer dispersion contains pigments, matting agents, light stabilizers, flame retardants, antioxidants, anti-static agents, anti-smudge agents, anti-squeak agents, thickeners, especially polyurethanes. at least one additive selected from thickeners, waterproof agents, anti-oil agents and hollow microspheres based on In one embodiment of the invention, the aqueous polymer dispersion contains up to a total of 20% by weight of additives.

The aqueous polymer dispersion can additionally contain one or more organic solvents. Suitable organic solvents are, for example, alcohols such as ethanol or isopropanol, and in particular glycols, diglycols, triglycols or tetraglycols, and glycols dialkoxylated or preferably monoalkoxylated with C ₁ -C ₄ -alkyl, diglycol, triglycol or tetraglycol. Examples of suitable organic solvents are ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 1,2-dimethoxyethane, methyltriethylene glycol (“methyltriglycol”) and triethylene glycol n-butyl ether (“butyltriglycol”).

In one embodiment of the invention, the aqueous polymer, especially the polyurethane dispersion, does not contain any propylene carbonate.

In a preferred embodiment, the polyurethane layer (C) is formed from an aqueous polyurethane dispersion optionally comprising at least one crosslinker C, the at least one crosslinker C being, as defined above, at least one at least one polyisocyanate P optionally blocked with a blocking agent BA of

In one embodiment of the invention, the aqueous polyurethane dispersion for producing polymer layer (C) comprises 0.1 to 5% by weight of dipropylene glycol dimethyl ether and/or 1,2-propanediol diacetate. In a particularly preferred embodiment, suitable crosslinkers C are as a 1 to 80% by weight solution in dipropylene glycol dimethyl ether and/or 1,2-propanediol diacetate, preferably dipropylene glycol dimethyl ether and/or 1,2 - added as a 30 to 75% by weight solution in propanediol diacetate to the aqueous polyurethane dispersion for the production of at least one polymer layer (C). In a particularly preferred embodiment, the polyisocyanate crosslinker C is used as a 30 to 75% by weight solution in dipropylene glycol dimethyl ether and/or 1,2-propanediol diacetate for the production of at least one polymer layer (C). It is added to an aqueous polyurethane dispersion for

After curing of the polymer layer (C), it is separated from the mold, for example by peeling it off, to obtain a polyurethane film forming the polymer layer (C) in the multilayer composite system according to the invention.

In a preferred embodiment of the invention, the template can also act as a protective layer, which can only be removed after fabrication of the actual multilayer composite system.

In step (b), the adhesive polymer is applied in solid form to the film (A) and/or polyurethane layer (C).

Adhesive polymers in solid form (such as adhesive grids, adhesive webs or adhesive films) can be applied according to methods known per se, in particular by mounting or pressing. Application can be carried out continuously or batchwise. The solid form of the adhesive polymer can be provided as a rolled product.

In another form, the adhesive polymer is applied in solid form to the polyurethane layer (C).

In another form, the adhesive polymer is applied in solid form to the film (A) and polyurethane layer (C).

In a preferred form, the adhesive polymer is applied to film (A) in solid form.

In step (c) the polyurethane layer (C) is combined with the film (A).

Generally, polyurethane layer (C) is combined with film (A) such that a layer of adhesive polymer is present between polyurethane layer (C) and film (A).

The adhesive polymer is largely cured, for example thermally, by actinic radiation or aging to obtain the multilayer composite according to the invention. Curing is preferably carried out thermally.

Compression of the composite system is also possible using, for example, a calendar. Suitable contact pressures may be in the range 1 to 20 bar, preferably 1.5 to 10 bar and especially 2 to 5 bar. Suitable contact times may range from 10 seconds to 100 minutes, preferably 30 seconds to 30 minutes, especially 1 to 10 minutes. Suitable contact temperatures may range from 80°C to 160°C, preferably from 90°C to 150°C, especially from 100°C to 140°C.

Multilayer composites produced according to the method according to the invention present various advantages:
The multilayer composites produced according to the method according to the invention have pleasant visual and tactile properties and exhibit surprisingly good mechanical properties such as rubbing fastness or buckling strength. In addition, these multilayer composites exhibit good functional properties and can be satisfactorily cleaned, for example using mechanical or chemical cleaning, for example supercritical carbon dioxide, or organic solvents such as hydrocarbons or halogenated hydrocarbons. can be done. In particular, these multilayer composites exhibit excellent storage and aging properties, especially hot light aging properties, and hydrolysis properties. In addition, the aqueous polymer dispersions used have a long shelf life, so that the composite materials produced according to the method according to the invention exhibit a very constant quality. Furthermore, it has been shown that the composite material produced according to the method according to the invention is adhesive-free immediately after production and can be stacked, rolled or otherwise stored very quickly after production.

TPU film 1: colorless transparent film of thermoplastic polyurethane based on aromatic polyester polyurethane, density 1.21 g/cm ³ (DIN 53479), melting point 140° C.-155° C. (Kofler bank at 50 μm thickness) , Raw material Shore A hardness of about 86 (DIN53505), tensile strength longitudinal/lateral tensile strength 45 MPa, elongation at break longitudinal/lateral 490% (DIN EN ISO527-1, -3), from Gerlinger Industries (Nordlingen, Germany) "Thermo- commercially available as "plastische Polyurethanefolie 4119 (Thermoplastic Polyurethane Film 4119)".

TPU film 2: colorless opaque film of thermoplastic polyurethane based on aromatic polyester polyurethane, density 1.19 g/cm ³ (DIN 53479), melting point 165° C.-175° C. (Kofler bank at 50 μm thickness), raw material Shore A hardness of about 86 (DIN53505), tensile strength longitudinal/lateral tensile strength 40 MPa, elongation at break longitudinal/lateral 500% (DIN EN ISO527-1, -3), Gerlinger Industries (Nordlingen, Germany) "Thermo-plastische Polyurethanefolie 4120 ( Thermoplastic Polyurethane Film 4120)”.

TPU film 3: film of thermoplastic polyurethane, thickness 150 μm, melting point about 120° C., commercially available.

Polyamide film 1: colorless polyamide film made from caprolactam, hexamethylenediamine and adipic acid (copolyamide 6/66), melting point about 190°C.

Adhesive A: white web of copolyester, weight per unit area 8-60 g/m ² , melting point 87°-97° C., melt volume flow rate MVR 51 to 100 cm ³ /10 min, Protechnic S.M. A. (Cernay, France).

Adhesive B: white web of copolyamide, weight per unit area 8-60 g/m ² , melting point 98° C.-108° C., melt volume flow rate MVR 19 to 50 cm ³ /10 min, Protechnic S.M. A. (Cernay, France).

Adhesive C: white web of aliphatic thermoplastic polyurethane polyester, weight per unit area 12-70 g/m ² , melting point 105° C.-115° C., melt volume flow rate MVR 51 to 100 cm ³ /10 min, Protechnic S.M. A. (Cernay, France).

Melting points were determined by DSC according to ISO11357. Melt volume flow rate MVR was measured at 160° C. and 2.16 kg according to ISO 1133-1.

value® PToM: aqueous anionic polyurethane dispersion, solids content 31-38% by weight, pH 6-8.5, run-off time 10-20 seconds (DIN 53211, 4 mm at 20° C.).

Pigment: Aqueous black pigment preparation commercially available as Luconyl® NG Black 0066 from BASF SE.

value® Haerter (curing agent) CI: 50-70% by weight solution of polyfunctional oligomeric isocyanate based on 1,6-hexamethylene diisocyanate commercially available from BASF SE.

General manufacturing method:
step a)
A silicone mold with the desired pattern was prepared according to the state of the art.

A polyurethane layer was formed on the mold by spraying the hot mold with an aqueous polyurethane dispersion containing value® PToM, value® HaerterCI, and state-of-the-art pigments.

step b)
Adhesive A, B or C was cut to the size of the film and applied to the film by hand.

step c)
The polyurethane layer was peeled from the mold and the adhesive was placed between the polyurethane layer and the film and combined with the overlying film.

The composite material thus obtained was pressed at 130° C.-135° C. for 3 or 5 minutes at a pressure of 3 mPa.

Examples 1-9: Composites on TPU Films Multilayer composites based on TPU films (TPU film 1, TPU film 2 and TPU film 3) were produced according to the general production method.

Adhesion of the composite layers was manually tested and evaluated qualitatively. The results are summarized in Table 1.

Example 10 Composite on Polyamide Film A multilayer composite based on Polyurethane film 1 and Adhesive A was prepared according to the general manufacturing method and tested for adhesion as in Examples 1-9. Adhesion was very good.

Claims (13)

(A) films made of polyurethane or polyamide;
(B) a tie layer made of a thermoplastic adhesive polymer having a melting point of 70° C. to 130° C.; and (C) a polyurethane layer, comprising:
here,
a) forming said polyurethane layer (C) using a mold;
b) applying said adhesive polymer in solid form to said film (A) and/or polyurethane layer (C); ) and said film (A) so as to be present between said film (A). 2. The method of claim 1, wherein the film is made of thermoplastic polyurethane or of aliphatic polyamide. 3. A method according to claim 1 or 2, wherein the film is made of thermoplastic polyurethane. 4. The method of any one of claims 1-3, wherein the film has a thickness of 1 to 500 [mu]m. 5. Process according to any one of the preceding claims, wherein the adhesive polymer in step b) has a weight per unit area of 5 to 100 g/m ^<2> . 6. Any one of claims 1 to 5, wherein the adhesive polymer in step b) has a melt volume flow rate MVR of 10 to 100 cm ³ /10 min measured at 160° C. and 2.16 kg according to ISO 1133-1. The method described in section. 7. A method according to any one of the preceding claims, wherein in step b) the adhesive is applied in the form of an adhesive grid, adhesive web or adhesive film. 8. The method of any one of claims 1-7, wherein the adhesive polymer has a melting point between 80<0>C and 125<0>C. 9. A method according to any one of the preceding claims, wherein the adhesive polymer is based on polyurethane, polyamide, polyester or polyolefin. 10. A method according to any one of the preceding claims, wherein the polyurethane layer (C) presents a pattern. 11. A method according to any one of the preceding claims, wherein said tie layer (B) is a perforated layer of cured adhesive polymer. 12. A method according to any one of the preceding claims, wherein the mold is a silicone mold structured using laser engraving. 13. Any of claims 1 to 12, wherein the wells are incorporated into the mold during structuring of the mold using a laser, the wells exhibiting an average depth in the range of 50 to 250 μm and center-to-center spacing in the range of 50 to 250 μm. or the method described in paragraph 1.